﻿//////////////////////////////////////////////////////////////////////////
/*
Copyright (c) 2011-2015 Kaiming Yi
	
	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:
	
	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.
	
	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	THE SOFTWARE.
	
*/
//////////////////////////////////////////////////////////////////////////



//////////////////////////////////////////////////////////////////////////
//
// Name:   	gkIterator.h
// Desc:	doc from ogre
// 描述:	ogre拷贝过来的工具，包装了迭代器
// 
// Author:  Kaiming-Desktop	 
// Date:	11/24/2010 	
// 
//////////////////////////////////////////////////////////////////////////
#pragma once

template <typename T, typename IteratorType, typename ValType>
class IteratorWrapper
{

private:
	/// Private constructor since only the parameterised constructor should be used
	IteratorWrapper();

protected:
	IteratorType mBegin;
	IteratorType mCurrent;
	IteratorType mEnd;


public:

	/// type you expect to get by funktions like peekNext(Value)
	typedef ValType ValueType;
	/// type you expect to get by funktions like peekNext(Value)Ptr
	typedef ValType* PointerType;

	/**
	\brief typedef to fulfill container interface

	Userfull if you want to use BOOST_FOREACH
	\note there is no distinction between const_iterator and iterator.
	\n keep this in mind if you want to derivate from this class. 
	*/
	typedef IteratorType iterator;

	/**
	\brief typedef to fulfill container interface

	Userfull if you want to use BOOST_FOREACH
	\note there is no distinction between const_iterator and iterator.
	\n keep this in mind if you want to derivate from this class. 
	*/
	typedef IteratorType const_iterator;





	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/
	IteratorWrapper ( IteratorType start, IteratorType end )
		: mBegin( start ), mCurrent ( start ), mEnd ( end )
	{
	}


	/** Returns true if there are more items in the collection. */
	bool hasMoreElements ( ) const
	{
		return mCurrent != mEnd;
	}


	/** Moves the iterator on one element. */
	void moveNext (  )
	{
		++mCurrent;
	}

	/** bookmark to the begin of the underlying collection */
	const IteratorType& begin() {return mBegin;}


	/** full access to the current  iterator */
	IteratorType& current(){return mCurrent;}

	/** bookmark to the end (one behind the last element) of the underlying collection */
	const IteratorType& end() {return mEnd;}


};



/** 
* 
* \brief Prepiared IteratorWrapper for container like std::vector 
*
* 
* \param T = Container eg vector 
* \param IteratorType  T::iterator or T::const_iterator
* 
* have a look at VectorIterator and ConstVectorIterator for a more concrete usage
*/
template <typename T, typename IteratorType>
class VectorIteratorWrapper : public IteratorWrapper<T, IteratorType, typename  T::value_type>
{

public:
	typedef typename IteratorWrapper<T, IteratorType, typename  T::value_type>::ValueType ValueType ; 
	typedef typename IteratorWrapper<T, IteratorType, typename  T::value_type>::PointerType PointerType ;


	/**
	* \brief c'tor
	* 
	* Constructor that provide a start and end iterator to initialise.
	* 
	* @param start start iterator 
	* @param end end iterator 
	*/
	VectorIteratorWrapper ( IteratorType start, IteratorType end )
		: IteratorWrapper<T, IteratorType, typename T::value_type>( start, end ) 
	{
	}


	/** Returns the next(=current) element in the collection, without advancing to the next. */
	ValueType peekNext (  ) const
	{
		return *(this->mCurrent);
	}

	/** Returns a pointer to the next(=current) element in the collection, without advancing to the next afterwards. */
	PointerType peekNextPtr (  )  const
	{
		return &(*(this->mCurrent) );
	}

	/** Returns the next(=current) value element in the collection, and advances to the next. */
	ValueType getNext (  ) 
	{
		return *(this->mCurrent++);
	}	

};


/** 
* 
* \brief Concrete IteratorWrapper for nonconst access to the underlying container
* 
* \param T  Container 
* 
*/
template <typename T>
class VectorIterator : public VectorIteratorWrapper<T,  typename T::iterator>{
public:
	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/	
	VectorIterator( typename T::iterator start, typename T::iterator end )
		: VectorIteratorWrapper<T,  typename T::iterator>(start , end )
	{
	}

	/** Constructor.
	@remarks
	Provide a container to initialise.
	*/
	explicit VectorIterator( T& c )
		: VectorIteratorWrapper<T,  typename T::iterator> ( c.begin(), c.end() )
	{
	}

};

/** 
* 
* \brief Concrete IteratorWrapper for const access to the underlying container
*
* 
* \param T = Container 
* 
*/
template <typename T>
class ConstVectorIterator : public VectorIteratorWrapper<T,  typename T::const_iterator>{
public:
	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/	
	ConstVectorIterator( typename T::const_iterator start, typename T::const_iterator end )
		: VectorIteratorWrapper<T,  typename T::const_iterator> (start , end )
	{
	}

	/** Constructor.
	@remarks
	Provide a container to initialise.
	*/
	explicit ConstVectorIterator ( const T& c )
		: VectorIteratorWrapper<T,  typename T::const_iterator> (c.begin() , c.end() )
	{
	}
};





/** 
* 
* \brief Prepiared IteratorWrapper for key-value container
*
* 
* \param T  Container  (map - or also set )
* \param  IteratorType T::iterator or T::const_iterator
* 
* have a look at MapIterator and ConstMapIterator for a concrete usage
*/
template <typename T, typename IteratorType>
class MapIteratorWrapper  : public IteratorWrapper<T, IteratorType, typename T::mapped_type>
{

public:
	/// redefined ValueType for a map/set
	typedef typename IteratorWrapper<T, IteratorType, typename  T::mapped_type>::ValueType ValueType ; 
	/// redefined PointerType for a map/set
	typedef typename IteratorWrapper<T, IteratorType, typename  T::mapped_type>::PointerType PointerType ;	

	///unused, just to make it clear that map/set::value_type is not a ValueType
	typedef typename T::value_type PairType ; 
	/// type you expect to get by funktions like peekNextKey
	typedef typename T::key_type KeyType;

	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/
	MapIteratorWrapper ( IteratorType start, IteratorType end )
		: IteratorWrapper<T, IteratorType, typename T::mapped_type>( start, end ) 
	{
	}

	/** Returns the next(=current) key element in the collection, without advancing to the next. */
	KeyType peekNextKey(void) const
	{
		return this->mCurrent->first;
	}


	/** Returns the next(=current) value element in the collection, without advancing to the next. */
	ValueType peekNextValue (  ) const
	{
		return this->mCurrent->second;
	}


	/** Returns a pointer to the next/current value element in the collection, without 
	advancing to the next afterwards. */
	const PointerType peekNextValuePtr (  )  const
	{
		return &(this->mCurrent->second);
	}


	/** Returns the next(=current) value element in the collection, and advances to the next. */
	ValueType getNext()
	{
		return ((this->mCurrent++)->second) ;
	}	


};




/** 
* 
* \brief Concrete IteratorWrapper for nonconst access to the underlying key-value container
*
* 
* \param T key-value container
* 
*/
template <typename T>
class MapIterator : public MapIteratorWrapper<T,  typename T::iterator>{
public:

	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/	
	MapIterator( typename T::iterator start, typename T::iterator end )
		: MapIteratorWrapper<T,  typename T::iterator>(start , end )
	{
	}

	/** Constructor.
	@remarks
	Provide a container to initialise.
	*/
	explicit MapIterator( T& c )
		: MapIteratorWrapper<T,  typename T::iterator> ( c.begin(), c.end() )
	{
	}

};


/** 
* 
* \brief Concrete IteratorWrapper for const access to the underlying key-value container
*
* 
* \param T key-value container
* 
*/
template <typename T>
class ConstMapIterator : public MapIteratorWrapper<T,  typename T::const_iterator>{
public:

	/** Constructor.
	@remarks
	Provide a start and end iterator to initialise.
	*/	
	ConstMapIterator( typename T::const_iterator start, typename T::const_iterator end )
		: MapIteratorWrapper<T,  typename T::const_iterator> (start , end )
	{
	}

	/** Constructor.
	@remarks
	Provide a container to initialise.
	*/
	explicit ConstMapIterator ( const T& c )
		: MapIteratorWrapper<T,  typename T::const_iterator> (c.begin() , c.end() )
	{
	}
};